@Max - Yes the HDR image is assembled from a sequence of LDR exposures - in this case typically with a constant f-stop (aperture) for uniform DoF, and a sequence of shutter speeds (eg, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500) - that is, spaced in 1EV increments.
I use Photosphere (Mac only) to assemble the LDRs into a HDR image and then I use various tone-mapping operators to produce the LDR. Then some post in PS. Photosphere is a great tool becuase it permits assembly of the HDRs (automatically, using the EXIF data in each LDR in the sequence) and then has panorama stitching built into the app so you can stitch HDRs together. There may be other apps that permit HDR stitching, but I use Photosphere and it does a nice job.
Another interesting app, as a PS plug-in is Flexify from Flaming Pear. This is a pretty cool plug-in that permits unwrapping and modification of various projections for images (i.e., going from mirror ball to lat-long, etc.).
http://www.flamingpear.com/flexify.html
great thread! thanks for sharing.
kirk